---
url: "https://onebag.travel/compare/9xu51kf1km/aer-travel-pack-2-small/ayd517mvmi/alpha-one-niner-sert-penumbra-2-0-backpack/"
title: "Aer Travel Pack 2 Small vs Alpha One-Niner SERT, PENUMBRA 2.0 Backpack"
description: "Aer Travel Pack 2 Small vs Alpha One-Niner SERT, PENUMBRA 2.0 Backpack: capacity, weight, dimensions and how many airlines accept each as a carry-on, side by…"
source: "https://onebag.travel/compare/9xu51kf1km/aer-travel-pack-2-small/ayd517mvmi/alpha-one-niner-sert-penumbra-2-0-backpack/"
---
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2.  [Carry-On Travel Backpacks](https://onebag.travel/carryons/)
3.  Aer Travel Pack 2 Small vs. Alpha One-Niner SERT, PENUMBRA 2.0 Backpack

# Aer Travel Pack 2 Small vs. Alpha One-Niner SERT, PENUMBRA 2.0 Backpack

Two carry-on travel backpacks, compared spec for spec.

## [Aer Travel Pack 2 Small](https://onebag.travel/carryon/9xu51kf1km/aer-travel-pack-2-small/)

by [Aer](https://onebag.travel/carryons/?brands=Aer)

![Front facing view of the Aer Travel Pack 2 Small](https://res.cloudinary.com/obt/image/upload/c_fill,w_400/v1620122261/carryons/Aer_Travel_Pack_2_Small_hkws6h.webp)

<table class="table table-sm cmp-spec mt-2"><tbody><tr><td>Capacity</td><td>28 L</td></tr><tr><td>Weight</td><td>1.7 kg</td></tr><tr><td>Dimensions</td><td>48×33×19 cm</td></tr><tr><td>Airline fit</td><td>92%</td></tr><tr><td>Price</td><td>$229</td></tr></tbody></table>

## Feature by feature

| Aer Travel Pack 2 Small | Feature | Alpha One-Niner SERT, PENUMBRA 2.0 Backpack |
| --- | --- | --- |
| Storage |
| 4 | Compression | 2 |
| None | Expanded Capacity | None |
| 1 | Opening | 1 |
| top, side | Passport | front |
| Y | Passthrough | Y |
| Carry |
| Y | Backpack | Y |
| optional | Hip Belt | optional |
| removable | Sternum Strap | removable |
| Inside |
| 16in | Laptop | 16in |
| 5 | Main Compartments | 5 |
| Y | Organizer | Y |
| Outside |
| × | Hard Shell | × |
| N | Rain-fly | N |
| 1, side | Water Bottle Holder | 2, side |
| Y | Water Resistant | Y |

<table class="cmp-material"><tbody><tr><td colspan="2">Material</td></tr><tr><td>700D Cordura</td><td>Available in: X-Pac X42, 500D, 630D HD</td></tr></tbody></table>

## [Alpha One-Niner SERT, PENUMBRA 2.0 Backpack](https://onebag.travel/carryon/ayd517mvmi/alpha-one-niner-sert-penumbra-2-0-backpack/)

by [Alpha One-Niner](https://onebag.travel/carryons/?brands=Alpha One-Niner)

![Front facing view of the Alpha One-Niner SERT, PENUMBRA 2.0 Backpack](https://res.cloudinary.com/obt/image/upload/c_fill,w_400/v1788990332/carryons/alpha-one-niner-sert-penumbra-2-0-backpack-ayd517mvmi.webp)

<table class="table table-sm cmp-spec mt-2"><tbody><tr><td>Capacity</td><td>21 L</td></tr><tr><td>Weight</td><td>1.5 kg</td></tr><tr><td>Dimensions</td><td>47×30×14 cm</td></tr><tr><td>Airline fit</td><td>93%</td></tr><tr><td>Price</td><td>$255</td></tr></tbody></table>

## Key differences between the Aer Travel Pack 2 Small and Alpha One-Niner SERT, PENUMBRA 2.0 Backpack

-   **Compression straps:** 4 on the Aer Travel Pack 2 Small; 2 on the Alpha One-Niner SERT, PENUMBRA 2.0 Backpack.
-   **Passport pocket:** Top, side on the Aer Travel Pack 2 Small; Front on the Alpha One-Niner SERT, PENUMBRA 2.0 Backpack.
-   **Water bottle pockets:** 1, side on the Aer Travel Pack 2 Small; 2, side on the Alpha One-Niner SERT, PENUMBRA 2.0 Backpack.

Both have: luggage passthrough, backpack straps, hip belt, sternum strap, laptop sleeve, built-in organizer, water resistant.

## Which airlines take each bag as a carry-on

We checked both bags against the carry-on size limits of 189 airlines. 174 accept both. 0 accept only the Aer Travel Pack 2 Small, and 1 accept only the Alpha One-Niner SERT, PENUMBRA 2.0 Backpack.

### Only the Alpha One-Niner SERT, PENUMBRA 2.0 Backpack fits

Air Niugini.

## Aer Travel Pack 2 Small vs. Alpha One-Niner SERT, PENUMBRA 2.0 Backpack: which should you pack?

The **Aer Travel Pack 2 Small** carries 7L more than the **Alpha One-Niner SERT, PENUMBRA 2.0 Backpack** (28L vs. 21L), while the **Alpha One-Niner SERT, PENUMBRA 2.0 Backpack** is the lighter pack at 1.5kg (vs. 1.7kg). For carry-on flexibility, the **Alpha One-Niner SERT, PENUMBRA 2.0 Backpack** fits 93% of the airlines we track — the higher of the two. If you prioritise packing volume, choose the Aer Travel Pack 2 Small; if you want to travel lighter, the Alpha One-Niner SERT, PENUMBRA 2.0 Backpack is the better call.